XML 68 R53.htm IDEA: XBRL DOCUMENT v3.20.2
Stock-based Compensation Plans - Additional Information (Detail) - USD ($)
12 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2016
Stock-Based Compensation Activity [Line Items]          
Unrecognized compensation costs, nonvested awards, amount $ 7,400,000        
Unrecognized compensation costs, nonvested awards, weighted average recognition period 2 years 2 months 12 days        
Stock-based compensation expense $ 5,453,000 $ 5,077,000 $ 4,807,000    
Dividend yield 0.00%        
Nonqualified Stock Options [Member]          
Stock-Based Compensation Activity [Line Items]          
Expiration period 7 years        
Stock-based compensation expense $ 2,500,000 2,200,000 1,600,000    
Aggregate intrinsic value, outstanding options 6,800,000        
Aggregate intrinsic value, exercisable options $ 5,800,000        
Weighted average remaining contractual life, options outstanding 4 years 3 months 18 days        
Weighted average remaining contractual remaining, options exercisable 3 years 2 months 12 days        
Intrinsic value, options exercised $ 2,000,000.0 300,000 12,100,000    
Nonqualified Stock Options [Member] | Employee [Member]          
Stock-Based Compensation Activity [Line Items]          
Vesting period 4 years        
Nonqualified Stock Options [Member] | Maximum [Member] | Director [Member]          
Stock-Based Compensation Activity [Line Items]          
Vesting period 1 year        
Restricted Stock Awards [Member]          
Stock-Based Compensation Activity [Line Items]          
Vesting period 3 years        
Stock-based compensation expense $ 2,000,000.0 1,700,000 $ 1,000,000.0    
Weighted average grant date fair value $ 3,900,000 $ 4,000,000.0      
Units granted 67,000 45,000 56,000    
Units outstanding 100,000 90,000 85,000 68,000  
Restricted Stock Units (RSUs) [Member]          
Stock-Based Compensation Activity [Line Items]          
Vesting period 3 years        
Stock-based compensation expense $ 600,000 $ 600,000 $ 500,000    
Weighted average grant date fair value $ 2,500,000 $ 2,800,000      
Units granted 18,000 12,000 22,000    
Units outstanding 65,000 62,000      
Deferred Stock Units [Member] | Director [Member]          
Stock-Based Compensation Activity [Line Items]          
Stock-based compensation expense $ 100,000 $ 100,000 $ 100,000    
Weighted average grant date fair value $ 1,300,000 $ 1,400,000      
Units outstanding 33,000 30,000      
Performance Shares [Member]          
Stock-Based Compensation Activity [Line Items]          
Vesting period       3 years 3 years
Performance Shares [Member] | Fiscal 2017 (2017 - 2019) [Member]          
Stock-Based Compensation Activity [Line Items]          
Fair value of stock units granted       $ 1,200,000  
Performance Shares [Member] | Maximum [Member]          
Stock-Based Compensation Activity [Line Items]          
Stock-based compensation expense $ 100,000 $ 400,000 1,500,000    
1999 Employee Stock Purchase Plan [Member]          
Stock-Based Compensation Activity [Line Items]          
Stock-based compensation expense 200,000 100,000 $ 100,000    
Annual compensation withheld, maximum limit 25,000        
Employee contributions in accrued compensation at period end $ 100,000 $ 100,000      
1999 Employee Stock Purchase Plan [Member] | Maximum [Member]          
Stock-Based Compensation Activity [Line Items]          
Common stock authorized, original authorization 600,000        
Annual compensation withheld 10.00%        
Vesting Anniversary [Member] | Nonqualified Stock Options [Member] | Employee [Member]          
Stock-Based Compensation Activity [Line Items]          
Vesting percentage 25.00%        
Vesting Anniversary [Member] | Restricted Stock Awards [Member]          
Stock-Based Compensation Activity [Line Items]          
Vesting percentage 33.00%        
Vesting Anniversary [Member] | Restricted Stock Units (RSUs) [Member] | Employee [Member]          
Stock-Based Compensation Activity [Line Items]          
Vesting percentage 33.00%        
2019 Equity Incentive Plan [Member]          
Stock-Based Compensation Activity [Line Items]          
Common stock authorized, original authorization 1,100,000        
Common stock authorized, shares remaining 839,000